merc 3.0 starter bolt?? (with pics)

[boaterntx]

1989 mcm 140/3.0l serial # 0c764786. I've owned the boat for 4yrs.

ok, been tracking down a metal to metal scrapping noise tha resembles a loose flywheel bolt. The noise comes and goes at random & is comming from the starter area. I Pulled the starter to look for any evidence & to my delight/surprise the outside (short) starter bolt was missing. I'm 80% sure this is the cause of my noise. I ordered a new bolt & go to install it but it's not going into the block. I grab a mirror & see what looks to be 1/2 of the old bolt. My question is, isn't there suppose to be a bolt here & what should I do? would you try to extract the bolt with the motor still in the boat or wait til the end of the season & pull the motor? the motor runs good and starts just fine every try. The amount of wear on the starter gear is minor, but i'm okay with buying a new starter or flywheel at the end of the season if need be. What do you guys think (see pics)?

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[chiefalen]

Re: merc 3.0 starter bolt?? (with pics)

i had to drill a hole and use a special tool to remove the bolt it called a bolt out it has reverse threads that lock in the hole u drill in the center of the bolt.no need to remove the engine.but do it now alot of torque on the starter and can snap the other bolt while your on the water and u go to start it. good luck just curious did u ever change the starter and not install the bracket that mount to the front of the starter and block?if u didnt insatall the bracket your gonna keep replacing bolts.

 

[Capt Ken]

Re: merc 3.0 starter bolt?? (with pics)

That bolt does go through and you should be able to see the top of it or the hole its in. It's unlikely you can get a drill in there and drill a hole for a ez out and unscrew the bolt. It won't be tight but I don't think you can get straight enough from the top. Otherwise, you will need to pull the engine to get at it. Be very careful, if you screw the hole up, you've just screwed up your block. Just finished one. Pulled the engine, bolted it up on the engine stand and flipped it upside down to make it easy to get out. Nothing worse than laying on your back trying to drill up on a swinging engine.

 

[45Auto]

Re: merc 3.0 starter bolt?? (with pics)

I personally would be scared to run it on one bolt. Lots of torque being applied to the flywheel by the starter, lots of opportunity for some real expensive damage to happen. And it'll probably happen way out on the water with no one else around - something's moving around causing that scraping noise you're hearing ................. but apparently it's been running like that for at least 4 years so you just need to decide how lucky you are!!

If you have to use a mirror to see it, you obviously don't have real good access to the broken bolt. I have a 3.0 in a 16' bowrider, and it's not bad to get the bolts off to change the starter but no way there's room to get a drill under there and hold it straight to drill out the bolt. If it's rusted in bad enough to break in half (those are big, strong bolts) I doubt if an easy-out will be successful. And once you break the easy-out off in the bolt, you just made your problem LOTS worse!

My guess is you'll probably have to drill out the bolt to the inner diameter of the threads then retap the hole, or replace it with a Helicoil. Either one requires drilling a STRAIGHT hole in the center of the bolt or you'll probably never get the starter on again.

A 3.0 is easy to remove if you have a tree limb or overhead garage beams available. Took me about 2 hours to pull mine and 2 hours to get it back in. I would pull yours one Saturday, drill and retap the hole correctly, then be back out on the water Sunday.

 

[Limited-Time]

Re: merc 3.0 starter bolt?? (with pics)

Bondo posted a great procedure for your specific problem. As stated the fix requires removal and re-installation of the engine, but as noted above it's not a daunting task as it sounds. I'd try a search and see what comes up.

 

[chiefalen]

Re: merc 3.0 starter bolt?? (with pics)

as i posted before but left out the part where i shot super penetrating oil in the hole.waited about 5 minutes and shot it again.about 4 times.i used a mirror and drilled a hole in the bolt with a brand new bosch drill bit i bought in home depot.it was the best drill bit i could get.i borrowed this small hammer drill my friend got in drill package i think its a rigid not sure.y i had to do it was i replaced my old style starter that was original to the boat with a new style smaller starter i did not install the bracket from the front of the starter to the block.it snapped the small bolt.it at the time did not seem a daunting task.i fabricated a new bracket after that and installed it.it's what i did and i explained it the best way i can.good luck hope it works out for u.

 

[boaterntx]

Re: merc 3.0 starter bolt?? (with pics)

I have some experince using easy outs.. good & BAD. think i'm going to pull the motor tomorrow. better to take some extra time & work & do it right then struggle with it & do it twice.
Thanks

 

[erikgreen]

Re: merc 3.0 starter bolt?? (with pics)

I'd never use an easy out... if it snaps off you'll need a carbide drill to get the rest of it out.

I'd recommend just drilling the old bolt out.. much easier than drilling through the tip from an easy-out.

 

[45Auto]

Re: merc 3.0 starter bolt?? (with pics)

Good decision Boaterntx. I'm with Erikgreen on the easy-out. Had a few good experiences with easy-outs on fresh bolts and internal engine bolts, but nothing good on corroded-in situations like yours appears from the pics. Let us know how it works out.